Electrolytic device



' Aug; 26, 1941.

Filed Aug. 28. 1937 J. B. BRENNAN ELECTROLYTIC DEVICE INVENTOR. T05 5 PH B. BEEN/VAN ATTORNEYS Patented Aug. 26, 1 941 UNITED STATES PATENT OFFICE 2,253,504 ELECTROLYTIC DEVICE J oseph Brennan, Euclid, Ohio npplication August 28, 1937, Serial No. 161,480 13 clsiins. (01. 175-315) This invention relates to electrolytic devices and more particularly to the construction of anodes for electrolytic condensers of the type embodying filmed anodes and liquid electrolytes, although the invention can of course be applied to other types of electrolytic devices.

Anodes for ordinary electrolytic condensers of theliquid type have generally consisted of sheets or strips of aluminum foil folded or coiled into various shapes in order-to obtain a relatively large surface area of aluminum in a compact space. The aluminum foil has ordinarily been supported by a riser consisting of an aluminum rod, to which the foil strip is secured as by welding or riveting. Condensers of this type have generally given satisfactory service, but the anodes and risers have been relatively expensive and difliculties have arisen by reason of corrosion at the connections between the riser and the foil, perhaps due to the fact that the extruded risers and the rolled foil may have different characteristics. Also the joint between anode and riser is a point of relatively high resistance, and under some circumstances the contacting parts may become filmed, with the result v a single strip of aluminum foil. The riser preferably comprises a strip of aluminum foil bent along a line or lines extending longitudinally of the'riser in such a manner as to stiifen the foil to give it sufiicient strength and rigidity to support the anode within the container. According to preferred embodiments of the invention, the anode comprises a strip of aluminum foil preferably corrugated and forined into conical spiral convolu-tions surrounding the riser strip or into other compact forms, and the anode and riser are conveniently made in one piece. v Preferred forms of the invention are illustrated in the drawing, in which Figure 1 is a view partiallyin section showing a wet condenser embodying my invention; Figure 2 is a section taken along line [-2 of Figure 1; Figure 3 is a section taken along line 33 of. Figure 1; Figin one stage of the manufacturing method; Fig- ,ure 5 is a view similar to Figure 4 and illustrating a modified form of anode strip; Figure 6 is a section similar to Figure 3 but showing a modified form of support for the riser portion of the anode.

As illustrated in Figure l of the drawing, a condenser made according to my-invention may preferably comprise a can 10 which servesas a container for the electrolyte II and also functions as the cathode of the condenser. The clan is provided with a depending hollow neck portion I2 through which the riser It extends, the riser being supported by a rubber gromet l5 which is compressed into fluid tight engagement with the riser by deforming the neck portion l2 inwardly as at i6.

The riser I4 is formed as an integral part of the anode proper illustrated at It which preferably comprises a spirally wound strip of aluminum foil extending downwardly along the riser in a series of conical convolutions. The strip of foil is preferably corrugated as illustrated in the drawing for the purpose of increasing the area of the foil and also to make it possible to coil the strip along the riser more easily. The end of the foil may besecured to the lowerportion of the riser by spot welding or riveting as at i9.

Preferably the first step in shaping a unitary anode riser according to my invention is that the end of a strip of foil between suitably shaped bending rolls. 'None of the material of the strip is removed in this operation and the bending operation is carried out in such a manner as to produce a riser portion of ample strength and rigidity accurately tdfsupport the completed anode within the container. Obviously various other shapes may be given to the riser portion H. For example; the foil may be bent into-a v or U shape as distinguished from thesemicircular shape illustrated, or may be provided .witha corrugation or double curve as shown at Ila in Figure 5. In Figure 5, I have also shown the strip Ha as being perforated or pierced as at 2"). Under some conditions, it is advantageous to perforate or pierce the anode foil. This operation can carried out on the anodes 4 is an illustration of the anode strip when illustrated in both Figure 3 and Figure 4.

To complete the unitary anode and riser, the full is bent sharply with relation to the riser portion as indicated at 22 in Figure 1, then the foil may be coiled downwardly along the riser by rotating the riser in a suitable chuck while guiding the foil to produce the desired configuration. Preferably the foil is guided through corrugated rolls prior to coiling to produce the corrugations It as shown in the drawing. The film forming operation may be carried out on the strip of foil before fabricating the anodes, or if desired the anodes can be bent to shape and then pmvided with dielectric films.

The anodes may be conveniently supported within the condenser by a rubber gromet l5 which may consist ofa short piece of semi-soft rubber provided with a slit to receive the riser ll as illustrated in Figure 3, or as shown in Figure 8 the gromet may be formed of two complementary parts 23 and 24 which are shaped to engage the riser Ila as shown. In either case the riser will be rigidly supported within the neck portion I2 of the container and a leak proof joint will be made between the neck and the gromet in the riser when the neck is deformed inwardly as indicated at It in Figure 1.

In winding the foil downwardly along the riser, the conical convolutions are preferably pitched at a fairly steep angle such as that illustrated in the drawing and the inner edges of the convolutions are slightly spaced from the riser as shown at 26 in Figure 1, so that any gases generated in the operation of the condenser can travel upwardly along the conical convolutions to a region adjacent the riser. The gases may then flow through an unobstructed path to the upper part of the condenser and be discharged therefrom through any suitable vent 21 formed in the closure for the condenser. The channel section of the riser portion I4 is particularly advantageous in this connection, as it provides ample space for the escape of gases and also allows free circulation of the electrolyte, thus making it possible to eliminate the perforations Ilb in most instances. These features contribute to the efilcient operation and long life of condensers made according to my invention.

Condensers made according to my invention can be produced rapidly and economically by simple apparatus. My anode construction provides for a relatively large surface area in a small space and at the same time insures adequate circulation of the electrolyte and adequately provides for the escape of gases. My anodes are extremely durable and free from corrosion because .the entire anode is preferably formed from a single piece or strip and there are no joints which are subiect to localized corrosion. Anodes made according to my invention may be readily treated to increase the effective surface area and ultimate capacity thereof preferably by the metal spraying method disclosed in my application Serial No. 662,107, filed March 22, 1933. when it is desired to so treat the anode foil, the etching or spraying operations, as the case may be. can be conveniently carried out on the strip of foil before any of the fabricating operations have taken-place. The strip of treated foil may then be provided with a dielectric film and then cut to the desired length and .bent into shape, or the strip may be cut and bent into shape and thereafter the individual electrodes may be sub- .iected to the final film forming operation in the usual manner.

Various modifications and changes in my inventioh all within the spirit and scope thereof will be evident to those persons skilled in the art. It is therefore to be understood that my patent is not limited to the preferred embodiments disclosed herein or in any manner other than by the scope of the appended claims when given the range of equivalents to which my patent may be entitled.

I claim:

1. In a condenser, a container for electrolyte, an anode disposed within the container, said anode comprising a strip of film forming metal wound into a plurality of helical convolutions,

the convolutions being of generally conical form,

and a riser for supporting the anode extending within the anode along the axis of the convolutions thereof.

2. In an electrolytic device, a container for electrolyte, an electrode disposed within the container, said electrode comprising a thin, transversely corrugated, metallic strip wound into a plurality of helical convolutions with the corrugations extendingin substantially radial directions, and a riser for supporting the anode extending within the electrode along the axis of the convolutions thereof.

3. In an electrolytic device, a container for electrolyte, an electrolyte therein, an electrode disposed within the container and immersed in the electrolyte, said electrode being formed of a thin fiat strip of film forming material wound into a. plurality of helical convolutions, and a substantially straight riser for supporting the electrode formed integrally therewith and extending within the electrode along the axis of the convolutions thereof, that portion of the riser extending within the electrode being immersed in the electrolyte. f

4.. A one-piece electrode and riser for electrolytic condensers or similar devices comprising a thin flexible strip of metallic foil having an end portion thereof bent along a straight line extending longitudinally of the strip to stiffen said portion and having the remaining portion of the strip coiled around the stiflened portion.

5. In an electrolytic device, a container for electrolyte, an electrode disposed within the container, said electrode comprising a corrugated metallic strip wound into a plurality of helical convolutions, the convolutions being of generally conical form, and a riser for supporting the anode and formed integrally therewith.

6. In an electrolytic device, a container for electrolyte, an electrode disposed within the container, said electrode comprising a corrugated metallic strip wound into a plurality of helical convolutions of generally conical form. I

7. In a condenser, a container for electrolyte having 9. depending neck portion of reduced diameter, an anode comprising a thin strip of sheet metal, a riser formed integrally therewith for supporting the anode within the container, said riser extending through the neck portion of the container and comprising a portion of said thin strip bent along the longitudinal axis of said portion in such a manner as to stiffen said portion.

8. A method of making electrodes for electrolytic'condensers and similar devices including the steps of bending the end portion of a strip of thin metallic foil along a line extending longitudinally of the strip to thereby stiffen the end portion, and coiling the remaining portion of the strip around the stiffened end portion.

9. A method of making electrodes for electroiytic condensers and similar devices including the steps of bending the end portion of a strip of thin metallic foil along a line extending longitudiriially of the strip to thereby stiffen the end portion, corrugating the remaining portion of the strip and coiling the corrugated portion around the stiffened end. portion.

10. A method of making a unitary electrode and riser for electrolytic condensers and similar devices including the steps of bending a portion of a thin metallic strip in such a manner as to stifien said portion, and bending the remainder ofsaid strip around the axis of said stiflfened portion.

11. In an electrolytic device, a containerfor electrolyte, an electrode disposed within the container, said electrode comprising a thin, transversely corrugated metallic strip having a pluporting said electrode formed integrally therewith and extending within the electrode along the axis of the convolutions thereof.

rality of hellcalconvolutions, and a riser for sup- I 

